ATH
Well-Known Member
I have a 243AI with a Shilen pre-fit barrel, which requires neck turning. I turned 300 Lapua 243Win brass then fire formed with 87Vmax loads near 243Win max loads. Had fun blowing up a lot of praire dogs to get formed cases.
Perhaps 200 of these cases were subsequently re-loaded with 105gr AMAX loads. This load was great fun, but after a high volume observation of the impact on primer pockets my next reloads will go down a half grain…hard on brass, though not evident during just a few rounds of load development.
So at this point I have perhaps 200 brass who have been fired once after fire forming, and another 100 which have been through fire forming but not fired with a full bore load. After prepping them all for loading at the more moderated 105gr AMAX load, in reloading I'm experiencing quite variable pressure in bullet seating. In the first 150 rounds, I've had 3 round which, after sizing with the same neck sizer bushing as all the others, will not hold the bullet.
To this point, the gun has been incredibly consistent to long ranges (800-900 yards). Out of 250 rounds fired during 3 days for prairie dog hunting, I experienced 3 rounds which landed considerably (several MOA) short of the target for no reason on a good hold.
I'm a bit concerned I'll experience increased vertical dispersion on this round of reloads. All of the brass were turned with a Hornady tool locked to the same setting. Anyone have a clue why I would now be experiencing an apparent difference in neck thickness after firing?
Perhaps 200 of these cases were subsequently re-loaded with 105gr AMAX loads. This load was great fun, but after a high volume observation of the impact on primer pockets my next reloads will go down a half grain…hard on brass, though not evident during just a few rounds of load development.
So at this point I have perhaps 200 brass who have been fired once after fire forming, and another 100 which have been through fire forming but not fired with a full bore load. After prepping them all for loading at the more moderated 105gr AMAX load, in reloading I'm experiencing quite variable pressure in bullet seating. In the first 150 rounds, I've had 3 round which, after sizing with the same neck sizer bushing as all the others, will not hold the bullet.
To this point, the gun has been incredibly consistent to long ranges (800-900 yards). Out of 250 rounds fired during 3 days for prairie dog hunting, I experienced 3 rounds which landed considerably (several MOA) short of the target for no reason on a good hold.
I'm a bit concerned I'll experience increased vertical dispersion on this round of reloads. All of the brass were turned with a Hornady tool locked to the same setting. Anyone have a clue why I would now be experiencing an apparent difference in neck thickness after firing?
